package leetcode;

public class Leetcode116 {
    class Node {
        public int val;
        public Node left;
        public Node right;
        public Node next;

        public Node() {}

        public Node(int _val) {
            val = _val;
        }

        public Node(int _val, Node _left, Node _right, Node _next) {
            val = _val;
            left = _left;
            right = _right;
            next = _next;
        }
    };

    public Node connect(Node root) {
        if(root==null||root.left==null){
            return root;
        }
        root.left.next = root.right;
        if(root.next!=null){
            root.right.next = root.next.left;
        }
        connect(root.left);
        connect(root.right);
        return root;

    }
}
